Rhizomes unbranched, erect, cylindric; stolons elongate, spongy, developing clusters of curved, fleshy, overwintering roots resembling tiny bananas at terminal nodes. Leaves: petiole glabrous. Leaf blade abaxially purplish with dark flecks, adaxially green, often with brown mottling, ovate to elliptic or nearly orbiculate, 7-18(-27) × 7-14(-18) cm, margins entire or sinuate; venation radiate and impressed centrally, without weblike pattern, principal veins 11-22; surfaces glabrous. Flowers floating or emersed, 6-11 cm diam., opening and closing diurnally, only sepals and outermost petals in distinct whorls of 4; sepals uniformly yellowish green, often red-tinted, evidently veined, lines of insertion on receptacle often slightly prominent; petals 12-30, yellow; stamens ca. 50-60, yellow, connective appendage minute or absent; filaments widest below middle, longer than anthers; pistil 7-10-locular, appendages at margin of stigmatic disk oblong-tapered, to 4.5 mm. Seeds globose, ca. 5 × 5 mm, uniformly covered with hairlike papillae 100-220 µm. 2n = 56.